Analysis and transition probabilities of the B1Πu → X1Σg + system of Na 2 excited by the 5017 Å line of the argon ion laser

Abstract

The fluorescence spectrum of Na 2 induced by the 5017.16 Å line of an argon ion laser has been analyzed. This work extends previous observations on Na 2 by using this excitation line. We have observed seven fluorescence series for the B 1 Π u → X 1 Σ g + band system corresponding to the excitation transitions: ν′ = 5, J′ = 37 ← ν″ = 6, J″ = 38; ν′ = 5, J′ = 88 ← ν″ = 5, J″ = 87; ν′ = 5, J′ = 124 ← ν″ = 3, J″ = 125; ν′ = 0, J′ = 42 ← ν″ = 2, J″ = 43; ν′ = 10, J′ = 78 ← ν″ = 9, J″ = 77; ν′ = 14, J′ = 68 ← ν″ = 12, J″ = 68 and ν′ = 15, J′ = 58 ← ν″ = 13, J″ = 58. The latter four series are reported for the first time. The radiative transition probabilities for the observed fluorescence series are calculated by using hybrid Perturbed-Morse-Oscillator (PMO)-Rydberg-Klein-Rees (RKR)-long range potential energy curves for the B 1 Π u and X 1 Σ g + states and ab initio transition dipole moment function. Radiative lifetimes of the rovibrational levels of the upper state pumped by the laser line have also been calculated. The transition probabilities and lifetimes are in good agreement with the corresponding observed measurements usually within the experimental uncertainty. From the rotational satellite structure of some bands, collision-induced transition rates and average cross sections have been determined.